The solution of using ESP32-C6 with SDIO as HOST_NG for I.MX93

[xiatian-xt]

Checklist

• Checked the issue tracker for similar issues to ensure this is not a duplicate.
• Described the feature in detail and justified the reason for the request.
• Provided specific use cases and examples.

Feature description

device tree
&usdhc3 {
pinctrl-names = "default", "state_100mhz", "state_200mhz";
pinctrl-0 = <&pinctrl_usdhc3>;
pinctrl-1 = <&pinctrl_usdhc3>;
pinctrl-2 = <&pinctrl_usdhc3>;
mmc-pwrseq = <&usdhc3_pwrseq>;
bus-width = <4>;
broken-cd;
keep-power-in-suspend;
status = "okay";
};

dmesg log
[ 9.629125] systemd-journald[172]: Received SIGUSR2 signal from PID 1, as request to rotate journal, rotating.
[ 9.645727] systemd-journald[172]: Vacuuming done, freed 0B of archived journals from /run/log/journal/8f1435.
[ 18.661352] platform imx93-lpm: deferred probe pending
[ 46.640645] esp32_hosted: esp_reset: Triggering ESP reset.
[ 57.495476] esp32_hosted: esp_reset: Triggering ESP reset.
[ 69.640427] esp32_hosted: esp_reset: Triggering ESP reset.
[ 92.243182] esp32_hosted: esp_reset: Triggering ESP reset.

The device tree information and dmesg information are as above. It seems that the SDIO is not functioning. I captured the signals with a logic analyzer and found that there is no clock signal. Therefore, I suspect that it is still an issue with my configuration. I'd like to inquire if there are any similar cases. Thank you!

Use cases

We are currently in the planning phase of designing an electroencephalogram (EEG) acquisition device that uses Wi-Fi to transmit EEG signals.

Alternatives

No response

Additional context

No response

[xiatian-xt]

root@atk-imx93:/usr/output/scripts# dmesg | grep mmc
[ 0.000000] Kernel command line: root=/dev/mmcblk0p2 rootwait rw console=ttyLP0,115200
[ 1.825077] mmc2: SDHCI controller on 428b0000.mmc [428b0000.mmc] using ADMA
[ 1.829471] mmc0: SDHCI controller on 42850000.mmc [42850000.mmc] using ADMA
[ 1.947540] mmc0: new HS400 Enhanced strobe MMC card at address 0001
[ 1.957963] mmcblk0: mmc0:0001 88A43A 14.6 GiB
[ 1.968411] mmcblk0: p1 p2
[ 1.983346] mmcblk0boot0: mmc0:0001 88A43A 4.00 MiB
[ 1.993683] mmcblk0boot1: mmc0:0001 88A43A 4.00 MiB
[ 2.003594] mmcblk0rpmb: mmc0:0001 88A43A 4.00 MiB, chardev (234:0)
[ 2.338501] sdhci-esdhc-imx 42860000.mmc: Got CD GPIO
[ 2.386552] mmc1: SDHCI controller on 42860000.mmc [42860000.mmc] using ADMA
[ 2.399806] EXT4-fs (mmcblk0p2): mounting ext3 file system using the ext4 subsystem
[ 2.423636] EXT4-fs (mmcblk0p2): recovery complete
[ 2.428596] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Quota mode: none.
[ 3.954622] EXT4-fs (mmcblk0p2): re-mounted. Quota mode: none.

[SohKamYung-Espressif]

@kapilkedawat Can you take a look to see if the device tree looks correct?

[kapilkedawat]

Hi @xiatian-xt could you paste the output of ls /sys/class/mmc_host/mmc2/ ?

Another user was using IMX93, may be we can get the working DT from there

[mantriyogesh]

In addition, @xiatian-xt, can you please capture a photo of your setup? Also please check if you have followed the Porting Guide? It has briefed about the expected external pull-up registered and expected lines.

Once you have PCB setup with the external pull-ups with expected lines and values, it should work. With wired setup, SDIO cannot function properly because of signal integrity issues. JFYI, we use 51KOhm in our setup.